<?php 

$username = $_POST['username'];

$preg = "/^[a-z][0-9a-z]{5,7}$/";

$c = preg_match($preg, $username);

if(!$c){
	$arr = array(
		'error'=>1,
		'info'=>'长度是以字母开头6-8位的字母或数字'
		);
	echo json_encode($arr);
	exit;
}

$users = include_once './user.php';

foreach ($users as  $user) {
	if($user['username']==$username){
		$arr = array(
		'error'=>1,
		'info'=>'用户名已存在'
		);
		echo json_encode($arr);
		exit;
	}
}


$arr = array(
		'error'=>0,
		'info'=>'用户可用'
		);
echo json_encode($arr);








 ?>